Sewing machines



United States Patent inventor SEWING MACHINES 11 Claims, 26 Drawing Figs.

u.s. c1

Field of Search References Cited UNITED STATES PATENTS 3/1885 Barsby Primary Examiner-Patrick D. Lawson Attorneys-W. Bigelow Hall and Richard A. Wise ABSTRACT: A lockstitch sewing machine having two adjustable sets of work piece feeding devices to enable one ply of a two ply work piece to be overfed or puckered with respect to the other at a point in advance of the sewing point so that one is held by the stitches in puckered relationship the other which remains essentially flat at the seam. The machine is particularly useful for sewing together the parts of a true moccasin comprising a vamp which passes beneath the wearers foot and has a long edge connected by a seam to the shorter edge of a plug.

Patented Sept. 29, 1970 3,530,808

In van 0 r Joesph f2. [ban/2172i 5y 72/5 Attorney Patented Sept. 29, 1970 Sheet Patented Sept. 29, 1970 Sheet Patented Sept. 29, 1970 3,530,808

Sheet 7 0113 Patented Sept. 29, 1970 3,530,808

Sheet Q of 13 Patented Sept. 29, 1970 3,530,808

Sheet 9 of 13 Patented Sept. 29, 1970 3,530,808

Sheet 10 0113 I Ans-m Patented Sept. 29, 1970 3,530,808

Sheet '11 of 13 Patented Sept. 29, 197 0 Sheet Q% 9% 3 $uw SEWING MACHINES The invention relates generally to improvements in lockstitch sewing machines and in some respects more specifically although not exclusively to such machines which are classified as heavily constructed and intended to operate upon resistive materials such as leather. Even more particularly, in one respect the invention relates to a lockstitch sewing machine having two adjustable feed systems and adapted to inserting a seam joining the edge of a plug to that of a vamp of a moccasin while causing the longer edge of the vamp to be puckered so as to match the edge length of the plug.

In the manufacture of a moccasin 'by a conventional method, a vamp and a plug are assembled together on a last, the edges of the two parts being joined together by a hand formed moccasin seam which not only joins together the two parts but also lasts them in the process. The hand sewing of moccasins is a tedious process requiring considerable skill and is accordingly very expensive. The resultant shoes are characterized by a comfortable fit resulting from the fact that the wearer's foot is surrounded by upper leather and further that the completed shoe is usually designed for great flexibility. Accordingly, the shoes find a ready and increasing market in spite of their high cost of production and the further fact that since the conventional moccasin seam is formed by hand, substantial variations in appearance must be tolerated because of the very great difficulty of obtaining uniformity in the product. In addition, the moccasin seam employed for joining the vamp to the plug is one in which two threads pass through stitch holes from one surface of the work to the other. In passing through the stitch holes the threads are not interlocked but merely twisted a half turn about each other. The result is that when either thread breaks as a result of flexure of the shoe during normal wear, the seam quickly unravels and for all practical purposes the shoe must be discarded since the seam cannot be repaired.

Because of the high cost of hand sewn moccasins, the lack of uniformity, and the lack of durability of the moccasin seam, many attempts have been made to develop a machine or machines for processing moccasins particularly the step of sewing the vamp to the plug. In general, however, these attempts have not attained commercial acceptance for either of two reasons: complexity and hence high cost or lack of reliability. One of the prior developments includes special lasting, trimming and sewing machines together with special footforms. This development requires a large capital investment for machines and a number of operators with the result that the potential savings are dissipated. In addition, the vamp in this process is adhesively secured temporarily to the plug to permit the sewing operation to be carried out on a special horn type lockstitch sewing machine. Any break in the adhesive joint before the seam is completed causes the product to be defective or at least requires a certain amount of reworking before sewing.

An object of the present invention is to provide a machine for joining together by their edges two parts of different lengths in such a way that the longer part is adjustably puckered during the sewing operation so as to match the length of the shorter one.

A more particular object is to provide a machine for joining the edge of a moccasin vamp to that of a moccasin plug by a lockstitch seam at the same time that the vamp is puckered to match its edge to that of the plug.

Still another object is to enhance the quality of moccasins by improving the durability of the seam which joins the vamp to the plug.

Still another object is to improve'the uniformity of moccasins by eliminating variations in stitch length, distance of stitch holes from the edge of the parts and variations in the distribution of puckering of the vamp around the plug.

The foregoing objects of the invention are achieved in a lockstitch sewing machine provided with two adjustable work feeding arrangements according to a feature of the present invention. One of the feeding arrangements is effective for advancing both plies of the work piece toward the sewing point.

The other, which is mounted for operation beneath a specially formed work support is operative on one ply only, the longer one, which it advances a greater distance than the shorter one is advanced during the formation of each stitch. The excess advance causes the longer ply to pucker and the amount of puckering is adjustable while the machine is in operation according to another feature of the invention so that corresponding points on the longer and shorter work pieces may be accurately matched by adjusting the amount of puckering after the stitching operation has been started.

The dual feed arrangement is combined with a novel work support according to another feature of the invention, adapted to receive a ply of a work piece on each of its upper and lower surfaces. In the illustrative embodiment, the machine is of the curved hook needle lockstitch type in which the work is advanced by a clamp feeding arrangement. The work support is reciprocated in a direction perpendicular to the plane of the needle and its two work engaging surfaces oriented at an acute angle. The upper surface cooperates with a presser foot to advance the shorter of the two work plies, the plug of the moc casin. At the same time, the longer ply, the vamp, is engaged by the lower surface of the work support where instrumentalities cooperate to overfeed the vamp to cause it to pucker at each stitch and thus bring corresponding points of plug and vamp at both sides of the moccasin into register.

According to a further feature of the invention, the puckering instrumentalities comprise an awl actuated in two directions toward and away from the work and toward and.

away from the plane of the needle. The awl cooperates with a retainer finger and with a machine awl which perforates the work for entry of the needle in the formation of each stitch.

The foregoing objects and features and many advantages of the present invention for the sewing of moccasins as well as for the formation of seams which are both functional and ornamental will be best understood from the following detailed description of an illustrative embodiment taken in connection with the accompanying drawings in which:

FIG. 1 is a view in right side elevation of a machine according to the present invention illustrating an auxiliary puckering device mounted outwardly from a work support of the machine;

FIG. 2 is a plan view of the machine of FIG. 1;

FIG. 3 is a view taken from the front and above the work support and depicting the construction of actuating connections for a vamp puckering awl;

FIG. 4 is a view taken approximately in the same direction as FIG. 3 but with a layer of parts removed for clarity, also illustrating actuating connections for vamp puckering devices;

FIG. 5 is a view in left side elevation of the actuating connections shown in FIGS. 3 and 4;

FIG. 6 is a view in perspective and on a reduced scale of driving connections for vamp puckering devices of the machine;

FIG. 7 is a view in perspective showing construction details of actuating connections for the vamp puckering awl;

FIGS. 8 and 9 are fragmentary detail views in perspective showing work release connections of the machine;

FIG. 10 is a view in perspective of a mechanism for adjusting the length of motion of the vamp puckering awl, with some of the parts shown in separated relationship for clarity;

FIG. 11 is a view in perspective showing the manipulation of a moccasin vamp and plug being joined together by a seam on the machine of the present invention;

FIG. 12 is a view in perspective showing a moccasin as sembly consisting of a vamp and plug after having been joined by a seam on the present machine but before the back of the vamp has been closed;

FIG. 13 is a view similar to FIG. 12 but showing the vamp closed;

FIG. 14 is a view showing a moccasin assembly such as that depicted in FIG. 13 but stretched over a last;

FIG. 15 is a fragmentary view in right side elevation showing the presentation of moccasin parts to the present machine;

FIG. 16 is a fragmentary view in front elevation partly in cross section and on an enlarged scale showing essentially the machine and moccasin parts of FIG.

FIGS. 17 to 22 are progressive views illustrating the feeding of moccasin parts and the formation of a stitch on the present machine;

FIG. 23 is a view similar to FIGS. 17 to 22 but illustrating the moccasin parts after having been secured together by several stitches;

FIG. 24 is a plan view of a moccasin vamp and plug being presented to a sewing machine according to the present invention at the beginning of the seam for joining the vamp to the plug; and

FIGS. 25a and 25b are time charts of the sewing machine.

The present machine which is suited to carrying out the method disclosed in my prior application for US. Letters Pat. Ser. No. 819,296, filed April 25, I969 includes stitch forming and work feeding instrumentalities of a curved hook needle lockstitch sewing machine similar to that disclosed in US Pat. No. 2,420,643, issued May 20, 1947 upon application of Fred Ashworth. The present machine which includes much of the general organization of the Ashworth machine has been modified to a great extent in its work feeding instrumentalities, stitch forming devices and timing to adapt them for the sewing of moccasin parts. As seen in FIGS. 1, 4, l5 and 22, the present machine is provided with stitch forming instrumentalities, including a curved hook needle 30, a curved work piercing machine awl 32 and a loop taker indicated generally at 34. Work feeding toward the stationary needle plane in which both the needle and the awl 32 oscillate, is accomplished by a clamp comprising a presser foot 36 and a work support indicated generally at 38 and later to be described in detail. The various instrumentalities of the machine are driven by cams and cranks mounted upon a main sewing shaft 40 which completes a revolution during the formation of each stitch. An auxiliary shaft 42 is interconnected with the main sewing shaft 40 by drive elements including a cogged belt 44 and also rotates a single revolution in synchronism with the main sewing shaft during the formation of each stitch. The auxiliary shaft 42 drives work feeding devices which will later be described in detail.

Turning briefly to FIGS. 11 and 22, it will be seen that in the operation of the present machine, a two layer work piece consisting typically of a moccasin plug 46 and a vamp 48 is presented to the machine in engagement with the work support 38, only a thin web portion 50 of which is shown in FIG. 22. The plug 46 is gripped between the presser foot 36 and the upper surface of the work support 38 which is longitudinally striated and designated by the reference character 52. The vamp 48 is operated upon beneath the work support 38 and is advanced by a puckering awl 54 cooperating with the machine awl 32 and a retaining finger 56 while the vamp is in engagement with the lower surface 60 of the work support 38. While the plug 46 is being advanced a stitch length by the work feeding clamp consisting of the work support 38 and the presser foot 36, the vamp 48 is overfed by the awl 54 to form a pucker such as that typically shown at 62 in FIG. 22. For puckering the vamp, the awl 54 penetrates part way into it and then advances toward the machine awl 32. The pucker 62 is formed by the longitudinal compression imparted to the vamp 48 by the awl 54 while the tendency of the vamp to slip to the left as seen in FIG. 22 and thereby to reduce the size of the pucker is resisted by the clamping action of the finger 56 which grips the vamp against the lower surface 60 of the work support. The puckering motion of the awl 54 ends when the awl 54 reaches the machine awl 32 which then penetrates the work piece in preparation for the formation of a stitch.

The awl 54, as seen in FIGS. 1 to 7 inclusive, is secured to the inner end ofa carrier 66 pivoted at 68 at the inner end ofa feed lever 70 which imparts to the carrier a horizontal oscillatory motion toward the work plane and return. In timed relationship with the motion of the lever 70, the carrier 66 is oscillated vertically, up to penetrate the vamp 48 in preparation for a work advancing stroke to the left as seen in FIGS. 2 and 3 and down out of engagement with the vamp at the end of the work advancing stroke prior to return of the feed lever 70 for the next work advancing motion. The lever 70 is pivoted at 72 on a slide 73 adjustable in and out on a frame 74 to accommodate the stitch forming and work feeding devices of the machine For reciprocating the awl carrier 66 vertically, the machine is provided, as best shown in FIG. 7, with an actuating mechanism including a cam 76 the periphery of which is engaged by a follower roll 78 rotatable at the inner end of a lever 80 pivoted at 82 on the frame 74. The follower roll is maintained in engagement with the contour of the cam 76 by a tension spring 84 stretched between the lever 80 and the frame 74. The lever 80 is connected by a link 86 to an outwardly extending arm of the carrier 66, the connection between the spring contracted expansible link 86 and the carrier 66 being in the form of a ball joint 88, which provides a pivotal connection allowing the necessary horizontal motion of the carrier 66.

The vamp puckering motion of the awl 54 may be increased or decreased while the machine is in operation to change the amount of puckering of the vamp between the stitches so that an exact match may be obtained between predetermined locations of final stitch holes on the plug 46 and on the vamp 48. Thus while the sewing is in progress the operator, realizing that insufficient puckering will cause a mark near the predetermined location of the last stitch on the vamp to extend beyond a corresponding mark on the plug, merely increases the horizontal awl motion and hence the puckering to obtain a closer match between the marks.

The vamp advancing motion of the awl 54 is derived from a barrel cam 90 best seen in FIGS. 1, 4, and 5 engaged by a follower roll 92 mounted at the inner end of an arm 94 of a bell crank also including another arm 96 radiating from a hub 98 as best seen in FIG. 10. The bell crank is pivoted on a shoulder screw 100 passing loosely through a clearance opening in the lever 70 and secured to an integral shelf of the frame 74 by a nut 102.

The bell crank 94, 96 receives a uniform motion during each sewing cycle but the motion of the bell crank is translated into an adjustable motion of the puckering awl 54 by a mechanism including an off-set adjusting lever 106 as best seen in FIGS. 2,3,5 and 10. The lever 106 is provided with an outwardly extending adjusting arm slidable over a motion limiting sector 108 into which are seated pins 110 and 112 for providing minimum and maximum limits in the amount of puckering imparted to the vamp as will now be seen. The lever 106 is pivoted at 114 and includes a short offset arm perforated near its end to provide a pivot at 116 for one end of a link 118 which at its other end is bifurcated to embrace a link 120. An actuating link 122 interconnects the actuating lever 70 to which it is pivoted at 124 with a pivot 126 which joins one end of the links 118 and 120 to the link 122. The link 120 is in turn received in the bifurcated end of the link 96 where it is engaged by a pivot pin 128. The mechanism which has just been described is interposed between the arm 96 of the bell crank and the actuating lever 70 and is adapted to translating the constant angular motion of the bell crank into a motion of adjustable length imparted to the actuating lever 70. In FIG. 10 the mechanism is shown in full lines in a condition to impart a minimum motion to the lever 70 whereas the position shown in dot and dash lines results in a maximum motion imparted to the lever 70. As shown in full lines the lever 106 is turned to a position near the counterclockwise extreme of its motion causing the pivot 116 to be located relatively near the pivot 124 as seen in FIG. 3 or to decrease the angle defined between the links 122 and 118. Under these conditions the motion of the pivot 126 about the pivot 116 includes a rela tively large component in a direction perpendicular to the link 122. On the other hand, when the lever 106 is adjusted to the dot and dash line position of FIG. 10, the pivot 116 is moved farther away from the pivot 124 than in the full line position.

As a result, the component of motion of the pivot 126 about the pivot 116 in the direction perpendicular to the link 122 is less and the component of motion in the direction of the length of the link 122 is greater. Accordingly, the motion of the carrier lever 70 in the puckering and return direction is greater when the adjusting lever 106 and the associated parts just described are in the dot and dash line position.

In order to prevent damage to the vamp, adjustment of the length of motion of the awl 54 which causes an immediate corresponding change in the position of the awl along the line of feed is accomplished only while the awl is out of engagement with the vamp 48. For this purpose there is provided an interlock connected to the adjusting lever 106 to prevent the lever from being moved while the awl 54 is penetrated into the vamp. The interlock as best seen in FIGS. 2, 3 and 10, is connected to the lever 106 by a link 132 having one end pivotally connected to the lever 106. The other end of the link 132 is pivoted to a gear sector 136 at 138. Locking pinions 140 and 142, are in mesh with the sector 136, the pinion 140 being rotatable about a fixed axis 144 on the frame 74 while the pinion 142 is rotatable about a pin 146 mounted on an unlocking lever 148 mounted for swinging movement about a pin 150 upon which the sector 136 is also rotatable. Mounted concentrically with the pinion 140 is a peripherally grooved disc 152 engaged by a complementary circumferential tongue on a disc 154 concentric with the pinion 142. A compression spring 156 is interposed between the lever 148 and a plate 158 fixed to the frame 74 for normally urging the tongue of the disc 154 into engagement with the groove of the disc 152. The tongue of the disc 154 is thus wedged into the groove and prevents rotation of the two pinions 140 and 142 which, since both pinions are in mesh with the sector 136, prevents a swinging motion of the sector and accordingly, through the link 132, locks the adjusting lever 106 in position during that part of each sewing cycle when the vamp is engaged by the awl 54. Mounted on the end of the release lever 148 remote from the pinion 142 is a follower roll 160 pressed by the spring 156 into engagement with the contour of a cam 162 secured to a shaft 164 and driven by the shaft 42. A lobe on the earn 162 presses the follower roll 160 away from the shaft 164 during a portion of the operation cycle of the machine while the puckering awl 54 is disengaged from the vamp 48. The motion of the follower roll 160 away from the shaft 164 causes the tongue of the disc 154 to be disengaged from the grooveddisc I52 thus freeing both pinions 140 and 142 for rotation. The sector I36 and the lever I06 are accordingly released for pivotal movement if it should be desirable to move the adjusting lever 106 in either direction to increase or decrease the amount of puckering motion imparted to the awl 54. Thus depending partly upon sewing speed, an adjustment of the puckering motion of the awl 54 may be accomplished without stopping or slowing down the machine either during a single sewing cycle, during the formation of a single stitch, or alternatively during the open portions when the lever 106 is pivotable during the formation of several consecutive stitches. However, no adjustment in the motion of the awl 54 can take place while the awl is in the vamp. There is accordingly no danger of damage to the vamp but advantages of adjusting the amount of puckering without stopping the machine are retained. The advantages include not only a substantial improvement in productivity but also an accurate visual indication for guiding the adjustment.

The cam 76 for imparting the work penetrating and withdrawal motion to the awl 54, the cam 90 for imparting a work puckering and return motion to the awl 54 and the cam 162 which releases the lock 130 are all mounted on and driven by the shaft I64 which is journaled in the frame 74.As best seen in FIG. 2 the intermediate shaft 42, which is driven from the main sewing shaft 40, is journaled in separated bearings in a bracket I66 secured to a machine main frame I68 so as to maintain the intermediate shaft 42 generally in alignment with the auxilary shaft I64. The shafts 42 and I64 are intercon- Actuating connections for the retaining finger 56 are seen in FIGS. 4 to 6 inclusive and comprise an actuating lever 172 pivoted near its outer end at 174 on the frame 74. At an intermediate point along its length, the lever 172 carries a follower roll 176 which engages the periphery of a cam 178 also mounted on the shaft 164. The lever 172 carries pivoted at its inner end, that most remote from the pivot 174, a. spring loaded buffer lever 180 bifurcated to embrace the inner end of the lever 172 and pivoted at 182. The buffer lever is urged in the clockwise direction about the pivot 182, as seen in FIGS. 4 and 5, by a tension spring 184 stretched between the outer end of the buffer lever and an anchor point on the frame 74. At an intermediate point along the length of the spring bearing arm, the buffer lever 180 has fixedly secured to it a lifting tab 186 the purpose of which will later be explained. At the forward end of the buffer lever there is provided a pivotal connection in the form of a ball joint 188 joining the lever 180 to the lower end of a vertical link 190, the upper end of which also has a ball joint 192 interconnecting it with the finger 56. The work support 38 provides a pivot 194 for the finger 56 which is oscillated in a vertical plane to bring its distal end into gripping engagement with the vamp in contact with the undersurface 60 of the work support 38. The gripping engagement of the finger 56 is provided as the contour of the cam 178 causes the pivot 182 on the lever 172 to swing upwardly against the urging of the spring 184. When the contour of the cam 178 allows the pivot 182 to descend, the finger 56 releases the vamp. The portion of the tab I86 overlying the lever 172 abuts the top surface of the lever I72 at this time to minimize the relative motion between the levers 172 and 180.

The work support 38 is an assembly comprising a wedge shaped portion including the upper and lower work contacting surfaces 52 and 60 as best seen in FIGS. 1, 3, 4, 5, l5 and 16. Above and inwardly from the upper surface 52 the work support 38 is formed with a shallow guide trough 200 to receive and guide the skived edge of the plug 46. Similarly the work support 38 is slotted below the surface 60 to provide a guide trough 202 to receive the skived edge of the vamp 48. The work support 38 is formed with integral mounting arms 204 by which it is secured to a work support carrier 206 of the machine for imparting a work advancing motion to the work support in unison with the presser foot 36. As best seen in FIG. 4, the thin web portion 50 located where the upper and lower surfaces 38 and 60 of the wedge portion come closest to converging, is longitudinally slotted as shown at 208 to provide clearance for the needle 30, the awl 32, the point of the puckering awl 54 and the thread interconnecting the plug 46 and the vamp 48 beyond, to the left of, the needle plane, the stationary plane in which both the needle 30 and the awl 32 oscillate. Since FIG. 16 depicts the work support 38 longitudinally along the center line of the slot 208, the plug 46 and the vamp 48 are shown in contact to the left of the web portion 50.

The moccasin parts are steadied for presentation above and below the work support 38, on a table 210 seen in FIGS. 1, 11 and 15 mounted for limited pivotal movement and spring urged in a counterclockwise direction as seen in FIG. 1. The pivotal mounting is provided by a pair of aligned hinged pins 212 interconnecting movable hinge members 214 with a stationary upright portion of a transverse brace 216 which is fixedly secured to the frame 74 and provides a support for the inner end of the lever 70. A compression spring 218 shown in FIG. 15, urges the inner end of the table 210 upwardly into gripping engagement with the vamp 48 against the bottom surface 60 of the work support 38. The limited freedom of the table 210 under the urging of the spring 218 accommodates different vamp thicknesses and assists the machine awl 32, the puckering awl 54 and the retaining finger 56 in holding the vamp 48 in sewing position. Thelongitudinal striations of the upper surface 52 tend to direct the skived margin of the plug 46 into the guiding trough 200 whereas the smooth surface 60 permits the skived edge of the vamp 48 to be manipulated into the trough 202 with freedom to allow the vamp to be puckered as the margins outside the seam are equalized.

The machine is provided with manually operated connections shown in FIGS. 8 and 9 for conveniently releasing the moccasin parts. These connections include a multiple part actuating lever comprising a handle 220 pivoted on a pair of aligned hinge pins one of which is shown at 222 and connected through a spacer 224 to the upper end of the generally vertical offset lever 226. At its lower end, the lever 226 is pivotally connected at 230 to a generally inwardly and horizontally extending link 232 having a pivotal connection 234 with the lower end of a lever 236 mounted for swinging movement about the shaft 164. The lever 236 is formed with a laterally extending ear 238 underlying the tab 186. The handle 220 has fixedly secured to it, an offset inwardly arm 240 terminating in a finger 242 extending beneath a stud 244 which secures the ball of the joint 88 to the carrier 66 and extends outwardly from the ball. After the machine has been stopped, movement of the handle 220 in a counterclockwise direction as seen in FIG. 8, causes the finger 242 to lift the outer end of the carrier 66 thereby withdrawing the puckering awl 54 downwardly from the vamp 48. At the same time, the car 238 causes the buffer lever to be pivoted in the counterclockwise direction as seen in FIG. 9 about the pivot 182 which is then stationary and consequently to lower the link 190 causing the finger 56 to be swung downwardly away from the vamp. In addition, the basic machine is so constructed that it stops with both the needle 30 and awl 32 out of the work and the presser foot 36 lifted automatically to release the plug. Accordingly, both the plug 36 and the vamp 48 whether separated or joined by a seam are readily removed from the machine.

At the beginning of the sewing operation, the vamp 48 and the plug 46 are advanced toward the needle plane in essentially flat condition, the three dimensional shape of the moccasin being generated as the insertion of the seam joining the plug to the vamp progresses. As shown in FIG. 12, the backpart of the vamp may be left open while the seam joining the plug to the vamp is being inserted and the vamp closed only after the seam is completed. The vamp shown in FIG. 11, however, while not completely illustrated is transversely slightly bowed in the forepart because its backpart has already been closed, only the forepart remaining essentially flat at the start of the sewing operation. It will also be appreciated as the description of the machine sewing operation progresses that the steps being described may be performed by hand with simple hand held implements as indicated in my copending application.

In the time chart, FIG. 25, graphs 250 and 252 depict the position of the awl 32 and the needle 30 respectively. The work advancing motion of the feeding clamp comprising the presser foot 36 and the work support 38 which advance the plug 46 is illustrated by a graph 254. The vamp advance and back feeding motion of the puckering awl 54 are illustrated by a graph 256 whereas a second graph 258 depicts the motion of the awl 54 into and out of the vamp. The motion of the retaining finger 56 into and out of engagement with the vamp 48 is shown by a graph 260. Finally, the engagement and release of the lock 130 for controlling the mobility of the adjusting lever 106 is depicted by a graph 262.

Conditions obtaining at the zero position of the sewing cycle are depicted in FIG. 17 in which the awl 54 is shown still embedded in the vamp 48 while both the needle 30 and the awl 32 are disengaged from the work piece. At this time, the work feeding clamp comprising the presser foot. 36 and work support 38 is nearing the completion of its work advancing motion which will be terminated as shown at 264 at the 42 position of the graph 254 which denotes the end of the work advancing motion of the feed clamp. At the zero position as also depicted in FIG. 17, the finger 56 is out of engagement with the vamp 48.

As the puckering awl 54 is being withdrawn from the vamp 48, the machine awl 32 penetrates the vamp and the plug 46 in abutting relationship with the puckering awl. Since the work feeding clamp consisting of the presser foot 36 and the work support 38 is still advancing the plug 46 and the vamp 48 toward the needle plane, the penetration of the awl 32 occurs essentially in the same aperture in which the awl 54 was embedded and results in a minimum marking of the vamp 48. The penetration of the awl 32 into the vamp 48 and the plug 46 begins at about the 5 position of the machine cycle and continues until maximum penetration of the awl is attained at the 24 position. The awl 32 dwells in its position of maximum penetration until approximately the 78 position of the time chart is reached, when the awl begins its withdrawal motion to be followed by the entry of the needle 30 into the perforation already formed by the awl. The machine instrumentalities are depicted in FIG. 18 at about the 40 position of the sewing cycle, including the awl 32 at its greatest upward penetration of the moccasin parts occuring after the 24 position of the sewing cycle and the puckering awl 54 having been backfed starting approximately at the 12 position of the sewing cycle and terminating as indicated by a marker 268 at the 35 position. Thus the showing of FIG. 18 includes the puckering awl 54 as positioned during a dwell period which extends between the marker 268 at the 35 position and the 80 position indicated by a marker 270. However, the showing of FIG. 18 includes the work feeding clamp comprising the presser foot 36 and the work support 38 only the web portion 50 of which is shown, in the most leftward position before the start of a backfeeding motion indicated by the markers 264 and 266 at the 42 and 75 position respectively in the graph 254. At that time the awl 54 as indicated by the graph 258 is out of engagement with the vamp 40 having terminated its disengagement at approximately the 17 position of the sewing cycle and continuing to dwell out of engagement until the 50 position of the sewing cycle marked at 272 is reached. As shown by the graph 260 the retaining finger 56 is also out of engagement with the vamp 48 and remains out of engagement until it commences to move toward the vamp at the 62 position of the sewing cycle as indicated by a marker 276. Finally as is indicated by the graph 262, the lock 130 is released and remains so until the 50 position of the sewing cycle is reached as indicated by a marker 280. The fact that the lock 130 is released permits the adjustment of the length of the puckering motion of the awl 54 at this time.

The showing of FIG. 19 is that of the relative positions of the machine instrumentalities at approximately the position of the machine cycle. At that time, the awl 32 as shown by the graph 250 continues to dwell in its highest position while the needle 30, which is not shown, has started to move toward the work piece but is not yet in engagement with it. The backfeeding motion of the feed clamp consisting of the presser foot 36 and the work support 38 is almost complete having only 5 of sewing cycle remaining before its termination at the position as indicated by the marker 266 on the graph 254. The puckering awl 54 continues to dwell in position ready to engage the vamp 48 for its next puckering motion which starts at the position of the sewing cycle as indicated by the marker 270. At the same time the awl 54 as indicated by the graph 260 is in the process of approaching the vamp 48, commencing at the 50 position as indicated by the markr 272 and terminating at the 80 position of the sewing cycle as indicated by a marker 274. The finger 56 is approaching the vamp 48 which it will clamp at the 82 position of the sewing cycle as marked at 278. Finally the lock 130 is in the process of being engaged which is completed at the 80 position of the sewing cycle as indicated by a marker 282 on the graph 262.

In FIG. 20, the machine instrumentalities are shown in their relative positions at approximately the position of the sewing cycle when the awl 32 as indicated by the graph 250 is withdrawing from the work piece and the needle 30 as shown by the graph 252 is entering the awl perforation in the plug 46 and vamp 48. At this time the feeding clamp consisting of the presser foot 36 and work support 38, having been backfed, is near the beginning of a dwell extending between the 75 and the l97 positions of the sewing cycle as defined by markers 266 and 284 respectively in the graph 254. The finger 56 from the 82 position of the sewing cycle marked at 278 grips the vamp against the bottom surface of the work support 38 while the puckering awl 54 is fully embedded in the vamp as shown by the graph 260 and its puckering motion has already begun as shown by the graph 258. At this time since the awl 54 is in engagement with the vamp 48 the lock 130 is fully engaged as shown by the graph 262 and the length of the puckering awl motion may not be adjusted. In FIG. 21 the machine instrumentalities are shown in their relative locations approximately the 200 position of the sewing cycle. When the needle 30 having completed its deepest penetration of the work piece at about the l40 position of the sewing cycle and been threaded by having a loop of needle thread laid in its barb before withdrawing to a position in which the needle thread loop is spread for entry of the loop taker beak to interlock the needle thread with a locking thread to form a lockstitch. In FIG. 21 the needle as shown by the graph 252 has not yet reached its highest position around the 230 position of the sewing cycle when the needle thread loop is spread to be followed by a clipping motion most pronounced about the 310 position of the sewing cycle when the loop taker beak enters the spread needle loop which is released from the needle barb. As shown in FIG. 21 the awl 32 having been most remotely withdrawn about the 130 position of the sewing cycle is fully returning toward the work piece but has as yet no effect upon it. As shown by the graph 254, the work advancing motion of the feed clamp comprising the presser foot 36 and the work support 38 has begun at the 197 position marked at 284 on the graph 254 but the feeding motion of the clamp has proceeded almost imperceptibly. The puckering awl 54 however has advanced to a considerable extent and thus been effective to start generating the pucker 62. The puckering advance of the awl 54 continues through the 360 position of the sewing cycle as shown by the graph 256 while the awl continues in its most fully penetrated position until the 353 position of the sewing cycle is reached as indicated by a marker 292 on the graph 258. The finger 56 continues to clamp the vamp as 48 shown by the graph 260 and the clamping of the finger 56 does not start to be released until the 340 position of the sewing cycle has been reached as indicated by a marker 290. Finally there is shown for high speed machine operation in the graph 262, an early unlock arrangement of the lock 130 which is locked at the 200 position corresponding to the showing of the machine instrumentalities depicted in FIG. 21. In the high speed arrangement, the release period of the lock 130 is increased by starting the opening motion early at the 300 position of the sewing cycle and completing it at the 320 position of the sewing cycle as bounded by markers 286 and 288 respectively. Accordingly, while operating at high speed there is provided a longer period during which the length of motion of the puckering awl 54 may be adjusted by movement of the lever 106. The potential damaging effect of the awl upon the vamp 48 is minimized since the awl 54 has begun to withdraw from the vamp at the 353 position of the sewing cycle and its advancing of the puckering motion is decelerating during the latter part of the sewing cycle in preparation for a reversal to the backfeeding direction which occurs at about the 70 position of the next sewing cycle.

In FIG. 22 the stitches formed by the interlock of the needle thread loop shown on the needle in FIG. 21 and the locking thread has been set out in the body of the work and the machine instrumentalities are shown in approximately their relative locations at the 340 position of the sewing cycle, when the awl 32 shown by the graph 250 has not yet engaged the underside of the vamp 48. At this point, the work feeding clamp consisting of the presser foot 36 and the work support 38 is nearing the end of its work advancing motion as the awl 54 is completing its work puckering motion before starting to withdraw from the vamp as shown by the graphs 256 and 258 respectively.

In FIG. 23 the machine instrumentalities are shown also at about the 200 position of the sewing cycle generally as depicted in FIG. 21, but in this view, the plug 46 and the vamp 48 are joined by the first. few lockstitches which secure the vamp in puckered relationship to the plug. As shown in FIG.

24 which depicts the relative position of the stitch holes in the plug 46 and the vamp 48, the spacing 296 between stitch holes in the plug is less than the spacing 298 of the corresponding stitch holes in the vamp 48. The difference in the two spacings results in the amount of puckering produced by the vamp advancing motion of the awl 54.

The result of sewing together the vamp to the plug of moccasins with a lockstitch seam as shown in FIG. 23 is that the presence of the thread lock in the stitch holes provides an impediment to the unravelling of the seam which is not present in moccasins sewn by hand with conventional moccasin seams. The result is greater durability of the seam and hence of the moccasin itself.

I claim:

1. A machine for sewing together a first ply and a second ply of a workpiece comprising stitch forming instrumentalities including a needle actuated at a sewing point for forming stitches, an awl adapted to engage the second ply of the workpiece and movable toward the sewing point and actuating means for imparting to the awl a longitudinal work compressing motion in advance of the sewing point whereby portions of the margin of the second ply are joined by stitches in puckered relationship to the margin of the first ply.

2. A machine according to claim 1 further characterized in that the actuating means is adjustable while the machine is in operation for changing the longitudinal compressing motion of the awl.

3. A machine according to claim 2 further comprising interlocking means for preventing adjustment of the longitudinal work compressing motion of the awl while the awl is in engagement with the second ply.

4. A machine for sewing together a multi-ply workpiece including a relatively short ply and a relatively long one comprising lockstitch forming instrumentalities including a needle cooperating with the other stitch forming instrumentalities to form lockstitches at a sewing point, a retainer for preventing movement of the long ply in the work advancing direction and an awl actuated toward the sewing point to compress the long ply longitudinally before the two plies are locally secured by stitches whereby the long ply is puckered between stitch perforations.

5. A machine for sewing together true moccasin parts including a vamp and a plug, having stitch forming instrumentalities including a needle actuated at a sewing point, comprising a work support adapted to position the vamp and the plug in seam receiving relationship in the path of the needle, a puckering awl adapted to engage the vamp in advance of and movable toward the sewing point, means for imparting to the awl a motion toward the sewing point for longitudinally compressing the vamp whereby the margin of the vamp is puckered between stitch perforations.

6. A machine according to claim 5 further comprising a finger adapted to clamp the vamp against the work support to prevent slippage of the vamp as it is being longitudinally compressed by the motion of the awl. 7. A machine according to claim 5 further characterized in that the stitch forming instrumentalities are adapted to the formation of lockstitches and that the needle is a curved hook needle oscillated in a stationary plane.

8. A machine according to claim 7 further comprising a curved machine awl mounted for oscillation in the needle plane and adapted to penetrate the moccasin parts to form perforations prior to the entry of the needle.

9. A machine according to claim 8 further comprising a retaining finger adapted to grip the vamp adjacent the machine awl to resist slippage under the compression imparted to the vamp by the puckering awl.

10. A machine according to claim 5 further comprising means for adjusting the compressing motion of the puckering awl while the machine is in operation.

11. A machine according to claim 10 further comprising means for preventing the adjustment of the puckering awl motion while the puckering awl is in engagement with the vamp. 

